Dying Chinese Elm (Ulmus Parvifolia)

Hello, I have a bonsai since January 2017. I think it is Chinese elm (Ulmus Parvifolia). It has many diseases. I need HELP!!

About 2 months ago, it's started to shed it many leaves. First a leaf would get black spots and then turn yellow, then fall down. I think it was black spot disease. (Picture A's)

Later, about a month ago it's started to get white spots on some leaves and on the same leaves, it started having tiny black spotted white insects. I think these are two spotted spider mites. (Picture B's)

After seeing the insects I sprayed Mancozeb (fungisit) and Acetamiprid (pesticide). This did not improve the insects situation but it's had positive effect on black spot disease.

For the last 2 weeks I have been using NeemAzal on it's leaves and soil, once a week. It killed about the insects %80 percent, but it still has some insects. I sprayed water and ciggarette ashes mix once. And I'm waiting to see the results.

Last week I saw little white round insects on its soil. (I haven't picture of them) I treated this with Acetamiprid on its soil once.

See Picure C's for the most recent status of my bonsai.
Now, tips of some of its leaves turn brownish and fall down.
Most of its leaves now seem to be covered in dust. It's new buds develıp a little and then change in to darker colour and fall off.
Now It shed most many of leaves and it trubk is covered with a white layer.

What do you think? What should I do?? Help me...

spray on fungicides and insecticides need repeat applications...

generally 3 treatments about 10 days apart.

however, using systemic remedies will work from the inside out and generally only need to be applied once or twice per growing season.

Thank you for your answer. But Which insecticide or fungicide should I use? Can you help me?

I hope nobody gets mad at me for posting a video.
Please let me know if this is a no no.

This may not be directly addressing all your specific problems, but it is a good general health video and he does mention a systemic towards the end.

I've not used it (yet) but I just happened to see this video yesterday.

It looks like the soil is too wet.
Is it outside?

İt's look like wet beacuse I take a photo after give water to my bonsai. So is anybody help me? What should I do? Which insecticide or pesticide or maybe changing a pot? Please help me? What is that white bug in soil? How can I get rid of it? Many questions...

Thank you

Get it outside.

The "bug" on not in the soil is either mealy bug or white fly but the soil does look very wet. This species is hardy and must be outside especially where you are. Do not re pot there is no need. Learn how to water, it is the most fundamental of all things that need to be learned. Check the soil every day and water when the soil is almost dry. Put a drop and I mean drop of washing up liquid in a sprayer and this will kill the insects. Make sure you spray under the leaves. Do this every 10 days.
This should get rid of the insects.
What fertiliser are you using and how often?

Are you using tap water (from your faucet) on this tree?

Looks like what might also be some sign of mineral salts build up on the trunk base and top of the soil.

a very small bit of research would tell you what type of treatments are available in Turkey and so i can not tell you that.
but, most garden store varieties would work BUT READ THE LABEL to make sure it is safe for your tree.

Last status is it. It has new buds but they turn to brown. They become rotten. Why? I change pot. And cut %30 of rotten roots. I want to save buds!!!

??

Why have you not taken it to a Bonsai Nursery / Plant Nursery or Bonsai club to be looked at ?
Until.
Khaimraj

I am at Turkey unluckily. There is no bonsai hospital.